linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Qian Cai <cai@lca.pw>
To: Feng Tang <feng.tang@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Michal Hocko <mhocko@suse.com>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Stephen Rothwell <sfr@canb.auug.org.au>,
	Matthew Wilcox <willy@infradead.org>,
	Mel Gorman <mgorman@suse.de>, Kees Cook <keescook@chromium.org>,
	Luis Chamberlain <mcgrof@kernel.org>,
	Iurii Zaikin <yzaikin@google.com>,
	andi.kleen@intel.com, tim.c.chen@intel.com,
	dave.hansen@intel.com, ying.huang@intel.com, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/3] make vm_committed_as_batch aware of vm overcommit policy
Date: Wed, 27 May 2020 08:05:49 -0400	[thread overview]
Message-ID: <20200527120549.GA741@lca.pw> (raw)
In-Reply-To: <20200527104606.GE93879@shbuild999.sh.intel.com>

On Wed, May 27, 2020 at 06:46:06PM +0800, Feng Tang wrote:
> Hi Qian,
> 
> On Tue, May 26, 2020 at 10:25:39PM -0400, Qian Cai wrote:
> > > > > > [1] https://lkml.org/lkml/2020/3/5/57
> > > > > 
> > > > > Reverted this series fixed a warning under memory pressue.
> > > > 
> > > > Andrew, Stephen, can you drop this series?
> > > > 
> > > > > 
> > > > > [ 3319.257898] LTP: starting oom01
> > > > > [ 3319.284417] ------------[ cut here ]------------
> > > > > [ 3319.284439] memory commitment underflow
> > > 
> > > Thanks for the catch!
> > > 
> > > Could you share the info about the platform, like the CPU numbers
> > > and RAM size, and what's the mmap test size of your test program.
> > > It would be great if you can point me the link to the test program.
> > 
> > I have been reproduced this on both AMD and Intel. The test just
> > allocating memory and swapping.
> > 
> > https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/mem/oom/oom01.c
> > https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/mem/tunable/overcommit_memory.c
> > 
> > It might be better to run the whole LTP mm tests if none of the above
> > triggers it for you which has quite a few memory pressurers.
> > 
> > /opt/ltp/runltp -f mm
> 
> Thanks for sharing. I tried to reproduce this on 2 server plaforms,
> but can't reproduce it, and they are still under testing.
> 
> Meanwhile, could you help to try the below patch, which is based on
> Andi's suggestion and have some debug info. The warning is a little
> strange, as the condition is
> 
> 	(percpu_counter_read(&vm_committed_as) <
>                        -(s64)vm_committed_as_batch * num_online_cpus())
> 
> while for your platform (48 CPU + 128 GB RAM), the
> '-(s64)vm_committed_as_batch * num_online_cpus()'
> is a s64 value: '-32G', which makes the condition hard to be true,
> and when it is,  it could be triggered by some magic for s32/s64
> operations around the percpu-counter. 

Here is the information on AMD and powerpc below affected by this. It
could need a bit patient to reproduce, but our usual daily CI would
trigger it eventually after a few tries.

# git clone https://github.com/cailca/linux-mm.git
# cd linux-mm
# ./compile.sh
# systemctl reboot
# ./test.sh

== AMD ==
# lscpu
Architecture:        x86_64
CPU op-mode(s):      32-bit, 64-bit
Byte Order:          Little Endian
CPU(s):              128
On-line CPU(s) list: 0-127
Thread(s) per core:  2
Core(s) per socket:  32
Socket(s):           2
NUMA node(s):        8
Vendor ID:           AuthenticAMD
CPU family:          23
Model:               1
Model name:          AMD EPYC 7601 32-Core Processor
Stepping:            2
CPU MHz:             3184.974
CPU max MHz:         2200.0000
CPU min MHz:         1200.0000
BogoMIPS:            4391.87
Virtualization:      AMD-V
L1d cache:           32K
L1i cache:           64K
L2 cache:            512K
L3 cache:            8192K
NUMA node0 CPU(s):   0-7,64-71
NUMA node1 CPU(s):   8-15,72-79
NUMA node2 CPU(s):   16-23,80-87
NUMA node3 CPU(s):   24-31,88-95
NUMA node4 CPU(s):   32-39,96-103
NUMA node5 CPU(s):   40-47,104-111
NUMA node6 CPU(s):   48-55,112-119
NUMA node7 CPU(s):   56-63,120-127

# numactl -H
available: 8 nodes (0-7)
node 0 cpus: 0 1 2 3 4 5 6 7 64 65 66 67 68 69 70 71
node 0 size: 20028 MB
node 0 free: 3837 MB
node 1 cpus: 8 9 10 11 12 13 14 15 72 73 74 75 76 77 78 79
node 1 size: 0 MB
node 1 free: 0 MB
node 2 cpus: 16 17 18 19 20 21 22 23 80 81 82 83 84 85 86 87
node 2 size: 0 MB
node 2 free: 0 MB
node 3 cpus: 24 25 26 27 28 29 30 31 88 89 90 91 92 93 94 95
node 3 size: 0 MB
node 3 free: 0 MB
node 4 cpus: 32 33 34 35 36 37 38 39 96 97 98 99 100 101 102 103
node 4 size: 31391 MB
node 4 free: 21309 MB
node 5 cpus: 40 41 42 43 44 45 46 47 104 105 106 107 108 109 110 111
node 5 size: 0 MB
node 5 free: 0 MB
node 6 cpus: 48 49 50 51 52 53 54 55 112 113 114 115 116 117 118 119
node 6 size: 0 MB
node 6 free: 0 MB
node 7 cpus: 56 57 58 59 60 61 62 63 120 121 122 123 124 125 126 127
node 7 size: 0 MB
node 7 free: 0 MB
node distances:
node   0   1   2   3   4   5   6   7
  0:  10  16  16  16  32  32  32  32
  1:  16  10  16  16  32  32  32  32
  2:  16  16  10  16  32  32  32  32
  3:  16  16  16  10  32  32  32  32
  4:  32  32  32  32  10  16  16  16
  5:  32  32  32  32  16  10  16  16
  6:  32  32  32  32  16  16  10  16
  7:  32  32  32  32  16  16  16  10

== powerpc ==
# lscpu
Architecture:        ppc64le
Byte Order:          Little Endian
CPU(s):              128
On-line CPU(s) list: 0-127
Thread(s) per core:  4
Core(s) per socket:  16
Socket(s):           2
NUMA node(s):        2
Model:               2.2 (pvr 004e 1202)
Model name:          POWER9 (raw), altivec supported
CPU max MHz:         3800.0000
CPU min MHz:         2300.0000
L1d cache:           32K
L1i cache:           32K
L2 cache:            512K
L3 cache:            10240K
NUMA node0 CPU(s):   0-63
NUMA node8 CPU(s):   64-127

# numactl -H
available: 2 nodes (0,8)
node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63
node 0 size: 130138 MB
node 0 free: 125654 MB
node 8 cpus: 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127
node 8 size: 130781 MB
node 8 free: 124756 MB
node distances:
node   0   8
  0:  10  40
  8:  40  10

  reply	other threads:[~2020-05-27 12:05 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-08  7:25 Feng Tang
2020-05-08  7:25 ` [PATCH 1/3] proc/meminfo: avoid open coded reading of vm_committed_as Feng Tang
2020-05-15  7:22   ` Michal Hocko
2020-05-08  7:25 ` [PATCH 2/3] mm/util.c: make vm_memory_committed() more accurate Feng Tang
2020-05-15  7:23   ` Michal Hocko
2020-05-15  8:11     ` Feng Tang
2020-05-15  9:04       ` Michal Hocko
2020-05-15 13:01         ` Feng Tang
2020-05-08  7:25 ` [PATCH 3/3] mm: adjust vm_committed_as_batch according to vm overcommit policy Feng Tang
2020-05-08 11:24   ` Matthew Wilcox
2020-05-08 12:33     ` Feng Tang
2020-05-15  7:41   ` Michal Hocko
2020-05-15  8:02     ` Feng Tang
2020-05-15  9:08       ` Michal Hocko
2020-05-15 11:26         ` Feng Tang
2020-05-15  7:44   ` Michal Hocko
2020-05-15  8:38     ` Feng Tang
2020-05-21 21:27 ` [PATCH 0/3] make vm_committed_as_batch aware of " Qian Cai
2020-05-26 18:14   ` Qian Cai
2020-05-27  1:14     ` Andi Kleen
2020-05-27  1:43       ` Feng Tang
2020-05-27  1:46     ` Feng Tang
2020-05-27  2:25       ` Qian Cai
2020-05-27 10:46         ` Feng Tang
2020-05-27 12:05           ` Qian Cai [this message]
2020-05-27 13:33             ` Feng Tang
2020-05-27 15:42               ` Qian Cai
2020-05-28 14:18           ` Qian Cai
2020-05-28 15:10             ` Feng Tang
2020-05-28 15:21               ` Kleen, Andi
2020-05-29 15:43                 ` Feng Tang
2020-05-29 15:50                   ` Andi Kleen
2020-05-29 16:04                     ` Feng Tang
2020-05-28 15:48               ` Michal Hocko

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200527120549.GA741@lca.pw \
    --to=cai@lca.pw \
    --cc=akpm@linux-foundation.org \
    --cc=andi.kleen@intel.com \
    --cc=dave.hansen@intel.com \
    --cc=feng.tang@intel.com \
    --cc=hannes@cmpxchg.org \
    --cc=keescook@chromium.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mcgrof@kernel.org \
    --cc=mgorman@suse.de \
    --cc=mhocko@suse.com \
    --cc=sfr@canb.auug.org.au \
    --cc=tim.c.chen@intel.com \
    --cc=willy@infradead.org \
    --cc=ying.huang@intel.com \
    --cc=yzaikin@google.com \
    --subject='Re: [PATCH 0/3] make vm_committed_as_batch aware of vm overcommit policy' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
on how to clone and mirror all data and code used for this inbox